Novel silicone aliphatic amine curing agent for epoxy resin: 1,3-Bis(2-aminoethylaminomethyl) tetramethyldisiloxane. 2. Isothermal cure, and dynamic mechanical property

A multifunctional silicone-contained aliphatic polyamine, 1,3-bis(2-aminoethylaminomethyl) tetramethyldisiloxane (SFA), was originally employed to cure bisphenol A epoxy resin (DGEBA) isothermally, and the curing reaction of DGEBA–SFA was systematically investigated by DSC measurement at 55, 60, 65 and 70 °C. The model fitting kinetic analysis confirmed that the reaction rate could be well simulated with an autocatalytic Kamal model up to the onset of the diffusion control stage. Taking the diffusion effects into account, the extended Kamal model was applied to fit the experimental reaction rate, with an excellent agreement throughout whole reaction process. The multi-frequency dynamic mechanical analysis shows that the cured DGEBA–SFA appears in a β relaxation in low temperature and an α relaxation in higher temperature interval (>80 °C). The relaxation activation energies for α and β relaxations are 70.1 and 287.6 kJ/mol, respectively.

► A novel silicone-contained aliphatic polyamine (SFA) was employed as the curing agent for bisphenol A epoxy resin.
► The isothermal curing kinetics of DGEBA/SFA was systematically investigated by differential scanning calorimetry.
► The extended Kamal model was successfully applied in describing the cure reaction of DGEBA–SFA precisely in the entire conversion range.
► The DMA test shows β transition (at low temperature) and α relaxation (at high temperature). The α relaxation expresses much higher activation energy in comparison with other DGEBA/polyamine systems.